This is Info file ../../info/lispref.info, produced by Makeinfo version 1.68 from the input file lispref.texi. INFO-DIR-SECTION XEmacs Editor START-INFO-DIR-ENTRY * Lispref: (lispref). XEmacs Lisp Reference Manual. END-INFO-DIR-ENTRY Edition History: GNU Emacs Lisp Reference Manual Second Edition (v2.01), May 1993 GNU Emacs Lisp Reference Manual Further Revised (v2.02), August 1993 Lucid Emacs Lisp Reference Manual (for 19.10) First Edition, March 1994 XEmacs Lisp Programmer's Manual (for 19.12) Second Edition, April 1995 GNU Emacs Lisp Reference Manual v2.4, June 1995 XEmacs Lisp Programmer's Manual (for 19.13) Third Edition, July 1995 XEmacs Lisp Reference Manual (for 19.14 and 20.0) v3.1, March 1996 XEmacs Lisp Reference Manual (for 19.15 and 20.1, 20.2, 20.3) v3.2, April, May, November 1997 XEmacs Lisp Reference Manual (for 21.0) v3.3, April 1998 Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc. Copyright (C) 1994, 1995 Sun Microsystems, Inc. Copyright (C) 1995, 1996 Ben Wing. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that this permission notice may be stated in a translation approved by the Foundation. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided also that the section entitled "GNU General Public License" is included exactly as in the original, and provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that the section entitled "GNU General Public License" may be included in a translation approved by the Free Software Foundation instead of in the original English.  File: lispref.info, Node: Key Lookup, Next: Functions for Key Lookup, Prev: Active Keymaps, Up: Keymaps Key Lookup ========== "Key lookup" is the process of finding the binding of a key sequence from a given keymap. Actual execution of the binding is not part of key lookup. Key lookup uses just the event type of each event in the key sequence; the rest of the event is ignored. In fact, a key sequence used for key lookup may designate mouse events with just their types (symbols) instead of with entire mouse events (lists). *Note Events::. Such a pseudo-key-sequence is insufficient for `command-execute', but it is sufficient for looking up or rebinding a key. When the key sequence consists of multiple events, key lookup processes the events sequentially: the binding of the first event is found, and must be a keymap; then the second event's binding is found in that keymap, and so on until all the events in the key sequence are used up. (The binding thus found for the last event may or may not be a keymap.) Thus, the process of key lookup is defined in terms of a simpler process for looking up a single event in a keymap. How that is done depends on the type of object associated with the event in that keymap. Let's use the term "keymap entry" to describe the value found by looking up an event type in a keymap. (This doesn't include the item string and other extra elements in menu key bindings because `lookup-key' and other key lookup functions don't include them in the returned value.) While any Lisp object may be stored in a keymap as a keymap entry, not all make sense for key lookup. Here is a list of the meaningful kinds of keymap entries: `nil' `nil' means that the events used so far in the lookup form an undefined key. When a keymap fails to mention an event type at all, and has no default binding, that is equivalent to a binding of `nil' for that event type. KEYMAP The events used so far in the lookup form a prefix key. The next event of the key sequence is looked up in KEYMAP. COMMAND The events used so far in the lookup form a complete key, and COMMAND is its binding. *Note What Is a Function::. ARRAY The array (either a string or a vector) is a keyboard macro. The events used so far in the lookup form a complete key, and the array is its binding. See *Note Keyboard Macros::, for more information. (Note that you cannot use a shortened form of a key sequence here, such as `(control y)'; you must use the full form `[(control y)]'. *Note Key Sequences::.) LIST The meaning of a list depends on the types of the elements of the list. * If the CAR of LIST is `lambda', then the list is a lambda expression. This is presumed to be a command, and is treated as such (see above). * If the CAR of LIST is a keymap and the CDR is an event type, then this is an "indirect entry": (OTHERMAP . OTHERTYPE) When key lookup encounters an indirect entry, it looks up instead the binding of OTHERTYPE in OTHERMAP and uses that. This feature permits you to define one key as an alias for another key. For example, an entry whose CAR is the keymap called `esc-map' and whose CDR is 32 (the code for ) means, "Use the global binding of `Meta-', whatever that may be." SYMBOL The function definition of SYMBOL is used in place of SYMBOL. If that too is a symbol, then this process is repeated, any number of times. Ultimately this should lead to an object that is a keymap, a command or a keyboard macro. A list is allowed if it is a keymap or a command, but indirect entries are not understood when found via symbols. Note that keymaps and keyboard macros (strings and vectors) are not valid functions, so a symbol with a keymap, string, or vector as its function definition is invalid as a function. It is, however, valid as a key binding. If the definition is a keyboard macro, then the symbol is also valid as an argument to `command-execute' (*note Interactive Call::.). The symbol `undefined' is worth special mention: it means to treat the key as undefined. Strictly speaking, the key is defined, and its binding is the command `undefined'; but that command does the same thing that is done automatically for an undefined key: it rings the bell (by calling `ding') but does not signal an error. `undefined' is used in local keymaps to override a global key binding and make the key "undefined" locally. A local binding of `nil' would fail to do this because it would not override the global binding. ANYTHING ELSE If any other type of object is found, the events used so far in the lookup form a complete key, and the object is its binding, but the binding is not executable as a command. In short, a keymap entry may be a keymap, a command, a keyboard macro, a symbol that leads to one of them, or an indirection or `nil'.  File: lispref.info, Node: Functions for Key Lookup, Next: Changing Key Bindings, Prev: Key Lookup, Up: Keymaps Functions for Key Lookup ======================== Here are the functions and variables pertaining to key lookup. - Function: lookup-key KEYMAP KEY &optional ACCEPT-DEFAULTS This function returns the definition of KEY in KEYMAP. If the string or vector KEY is not a valid key sequence according to the prefix keys specified in KEYMAP (which means it is "too long" and has extra events at the end), then the value is a number, the number of events at the front of KEY that compose a complete key. If ACCEPT-DEFAULTS is non-`nil', then `lookup-key' considers default bindings as well as bindings for the specific events in KEY. Otherwise, `lookup-key' reports only bindings for the specific sequence KEY, ignoring default bindings except when you explicitly ask about them. All the other functions described in this chapter that look up keys use `lookup-key'. (lookup-key (current-global-map) "\C-x\C-f") => find-file (lookup-key (current-global-map) "\C-x\C-f12345") => 2 If KEY begins with the character whose value is contained in `meta-prefix-char', that character is implicitly removed and the modifier added to the key. Thus, the first example below is handled by conversion into the second example. (lookup-key (current-global-map) "\ef") => forward-word (lookup-key (current-global-map) "\M-f") => forward-word Unlike `read-key-sequence', this function does not modify the specified events in ways that discard information (*note Key Sequence Input::.). In particular, it does not convert letters to lower case. - Command: undefined Used in keymaps to undefine keys. If a key sequence is defined to this, invoking this key sequence causes a "key undefined" error, just as if the key sequence had no binding. - Function: key-binding KEY &optional ACCEPT-DEFAULTS This function returns the binding for KEY in the current keymaps, trying all the active keymaps. The result is `nil' if KEY is undefined in the keymaps. The argument ACCEPT-DEFAULTS controls checking for default bindings, as in `lookup-key' (above). (key-binding "\C-x\C-f") => find-file (key-binding '(control home)) => beginning-of-buffer (key-binding [escape escape escape]) => keyboard-escape-quit - Function: local-key-binding KEY &optional ACCEPT-DEFAULTS This function returns the binding for KEY in the current local keymap, or `nil' if it is undefined there. The argument ACCEPT-DEFAULTS controls checking for default bindings, as in `lookup-key' (above). - Function: global-key-binding KEY &optional ACCEPT-DEFAULTS This function returns the binding for command KEY in the current global keymap, or `nil' if it is undefined there. The argument ACCEPT-DEFAULTS controls checking for default bindings, as in `lookup-key' (above). - Function: minor-mode-key-binding KEY &optional ACCEPT-DEFAULTS This function returns a list of all the active minor mode bindings of KEY. More precisely, it returns an alist of pairs `(MODENAME . BINDING)', where MODENAME is the variable that enables the minor mode, and BINDING is KEY's binding in that mode. If KEY has no minor-mode bindings, the value is `nil'. If the first binding is not a prefix command, all subsequent bindings from other minor modes are omitted, since they would be completely shadowed. Similarly, the list omits non-prefix bindings that follow prefix bindings. The argument ACCEPT-DEFAULTS controls checking for default bindings, as in `lookup-key' (above). - Variable: meta-prefix-char This variable is the meta-prefix character code. It is used when translating a two-character sequence to a meta character so it can be looked up in a keymap. For useful results, the value should be a prefix event (*note Prefix Keys::.). The default value is `?\^[' (integer 27), which is the ASCII character usually produced by the key. As long as the value of `meta-prefix-char' remains `?\^[', key lookup translates ` b' into `M-b', which is normally defined as the `backward-word' command. However, if you set `meta-prefix-char' to `?\^X' (i.e. the keystroke `C-x') or its equivalent ASCII code `24', then XEmacs will translate `C-x b' (whose standard binding is the `switch-to-buffer' command) into `M-b'. meta-prefix-char ; The default value. => ?\^[ ; Under XEmacs 20. => 27 ; Under XEmacs 19. (key-binding "\eb") => backward-word ?\C-x ; The print representation ; of a character. => ?\^X ; Under XEmacs 20. => 24 ; Under XEmacs 19. (setq meta-prefix-char 24) => 24 (key-binding "\C-xb") => backward-word ; Now, typing `C-x b' is ; like typing `M-b'. (setq meta-prefix-char ?\e) ; Avoid confusion! ; Restore the default value! => ?\^[ ; Under XEmacs 20. => 27 ; Under XEmacs 19.  File: lispref.info, Node: Changing Key Bindings, Next: Key Binding Commands, Prev: Functions for Key Lookup, Up: Keymaps Changing Key Bindings ===================== The way to rebind a key is to change its entry in a keymap. If you change a binding in the global keymap, the change is effective in all buffers (though it has no direct effect in buffers that shadow the global binding with a local one). If you change the current buffer's local map, that usually affects all buffers using the same major mode. The `global-set-key' and `local-set-key' functions are convenient interfaces for these operations (*note Key Binding Commands::.). You can also use `define-key', a more general function; then you must specify explicitly the map to change. The way to specify the key sequence that you want to rebind is described above (*note Key Sequences::.). For the functions below, an error is signaled if KEYMAP is not a keymap or if KEY is not a string or vector representing a key sequence. You can use event types (symbols) as shorthand for events that are lists. - Function: define-key KEYMAP KEY BINDING This function sets the binding for KEY in KEYMAP. (If KEY is more than one event long, the change is actually made in another keymap reached from KEYMAP.) The argument BINDING can be any Lisp object, but only certain types are meaningful. (For a list of meaningful types, see *Note Key Lookup::.) The value returned by `define-key' is BINDING. Every prefix of KEY must be a prefix key (i.e., bound to a keymap) or undefined; otherwise an error is signaled. If some prefix of KEY is undefined, then `define-key' defines it as a prefix key so that the rest of KEY may be defined as specified. Here is an example that creates a sparse keymap and makes a number of bindings in it: (setq map (make-sparse-keymap)) => # (define-key map "\C-f" 'forward-char) => forward-char map => # (describe-bindings-internal map) => ; (Inserted in buffer) C-f forward-char ;; Build sparse submap for `C-x' and bind `f' in that. (define-key map "\C-xf" 'forward-word) => forward-word map => # (describe-bindings-internal map) => ; (Inserted in buffer) C-f forward-char C-x << Prefix Command >> C-x f forward-word ;; Bind `C-p' to the `ctl-x-map'. (define-key map "\C-p" ctl-x-map) ;; `ctl-x-map' => # ;; Bind `C-f' to `foo' in the `ctl-x-map'. (define-key map "\C-p\C-f" 'foo) => foo map => # (describe-bindings-internal map) => ; (Inserted in buffer) C-f forward-char C-p << Prefix command Control-X-prefix >> C-x << Prefix Command >> C-p tab indent-rigidly C-p $ set-selective-display C-p ' expand-abbrev C-p ( start-kbd-macro C-p ) end-kbd-macro ... C-p C-x exchange-point-and-mark C-p C-z suspend-or-iconify-emacs C-p M-escape repeat-complex-command C-p M-C-[ repeat-complex-command C-x f forward-word C-p 4 . find-tag-other-window ... C-p 4 C-o display-buffer C-p 5 0 delete-frame ... C-p 5 C-f find-file-other-frame ... C-p a i g inverse-add-global-abbrev C-p a i l inverse-add-mode-abbrev Note that storing a new binding for `C-p C-f' actually works by changing an entry in `ctl-x-map', and this has the effect of changing the bindings of both `C-p C-f' and `C-x C-f' in the default global map. - Function: substitute-key-definition OLDDEF NEWDEF KEYMAP &optional OLDMAP This function replaces OLDDEF with NEWDEF for any keys in KEYMAP that were bound to OLDDEF. In other words, OLDDEF is replaced with NEWDEF wherever it appears. The function returns `nil'. For example, this redefines `C-x C-f', if you do it in an XEmacs with standard bindings: (substitute-key-definition 'find-file 'find-file-read-only (current-global-map)) If OLDMAP is non-`nil', then its bindings determine which keys to rebind. The rebindings still happen in NEWMAP, not in OLDMAP. Thus, you can change one map under the control of the bindings in another. For example, (substitute-key-definition 'delete-backward-char 'my-funny-delete my-map global-map) puts the special deletion command in `my-map' for whichever keys are globally bound to the standard deletion command. - Function: suppress-keymap KEYMAP &optional NODIGITS This function changes the contents of the full keymap KEYMAP by making all the printing characters undefined. More precisely, it binds them to the command `undefined'. This makes ordinary insertion of text impossible. `suppress-keymap' returns `nil'. If NODIGITS is `nil', then `suppress-keymap' defines digits to run `digit-argument', and `-' to run `negative-argument'. Otherwise it makes them undefined like the rest of the printing characters. The `suppress-keymap' function does not make it impossible to modify a buffer, as it does not suppress commands such as `yank' and `quoted-insert'. To prevent any modification of a buffer, make it read-only (*note Read Only Buffers::.). Since this function modifies KEYMAP, you would normally use it on a newly created keymap. Operating on an existing keymap that is used for some other purpose is likely to cause trouble; for example, suppressing `global-map' would make it impossible to use most of XEmacs. Most often, `suppress-keymap' is used to initialize local keymaps of modes such as Rmail and Dired where insertion of text is not desirable and the buffer is read-only. Here is an example taken from the file `emacs/lisp/dired.el', showing how the local keymap for Dired mode is set up: ... (setq dired-mode-map (make-keymap)) (suppress-keymap dired-mode-map) (define-key dired-mode-map "r" 'dired-rename-file) (define-key dired-mode-map "\C-d" 'dired-flag-file-deleted) (define-key dired-mode-map "d" 'dired-flag-file-deleted) (define-key dired-mode-map "v" 'dired-view-file) (define-key dired-mode-map "e" 'dired-find-file) (define-key dired-mode-map "f" 'dired-find-file) ...  File: lispref.info, Node: Key Binding Commands, Next: Scanning Keymaps, Prev: Changing Key Bindings, Up: Keymaps Commands for Binding Keys ========================= This section describes some convenient interactive interfaces for changing key bindings. They work by calling `define-key'. People often use `global-set-key' in their `.emacs' file for simple customization. For example, (global-set-key "\C-x\C-\\" 'next-line) or (global-set-key [(control ?x) (control ?\\)] 'next-line) or (global-set-key [?\C-x ?\C-\\] 'next-line) redefines `C-x C-\' to move down a line. (global-set-key [(meta button1)] 'mouse-set-point) redefines the first (leftmost) mouse button, typed with the Meta key, to set point where you click. - Command: global-set-key KEY DEFINITION This function sets the binding of KEY in the current global map to DEFINITION. (global-set-key KEY DEFINITION) == (define-key (current-global-map) KEY DEFINITION) - Command: global-unset-key KEY This function removes the binding of KEY from the current global map. One use of this function is in preparation for defining a longer key that uses KEY as a prefix--which would not be allowed if KEY has a non-prefix binding. For example: (global-unset-key "\C-l") => nil (global-set-key "\C-l\C-l" 'redraw-display) => nil This function is implemented simply using `define-key': (global-unset-key KEY) == (define-key (current-global-map) KEY nil) - Command: local-set-key KEY DEFINITION This function sets the binding of KEY in the current local keymap to DEFINITION. (local-set-key KEY DEFINITION) == (define-key (current-local-map) KEY DEFINITION) - Command: local-unset-key KEY This function removes the binding of KEY from the current local map. (local-unset-key KEY) == (define-key (current-local-map) KEY nil)  File: lispref.info, Node: Scanning Keymaps, Next: Other Keymap Functions, Prev: Key Binding Commands, Up: Keymaps Scanning Keymaps ================ This section describes functions used to scan all the current keymaps, or all keys within a keymap, for the sake of printing help information. - Function: accessible-keymaps KEYMAP &optional PREFIX This function returns a list of all the keymaps that can be accessed (via prefix keys) from KEYMAP. The value is an association list with elements of the form `(KEY . MAP)', where KEY is a prefix key whose definition in KEYMAP is MAP. The elements of the alist are ordered so that the KEY increases in length. The first element is always `([] . KEYMAP)', because the specified keymap is accessible from itself with a prefix of no events. If PREFIX is given, it should be a prefix key sequence; then `accessible-keymaps' includes only the submaps whose prefixes start with PREFIX. These elements look just as they do in the value of `(accessible-keymaps)'; the only difference is that some elements are omitted. In the example below, the returned alist indicates that the key `C-x', which is displayed as `[(control x)]', is a prefix key whose definition is the keymap `#) 1 entry 0x8a2>'. (The strange notation for the keymap's name indicates that this is an internal submap of `emacs-lisp-mode-map'. This is because `lisp-interaction-mode-map' has set up `emacs-lisp-mode-map' as its parent, and `lisp-interaction-mode-map' defines no key sequences beginning with `C-x'.) (current-local-map) => # (accessible-keymaps (current-local-map)) =>(([] . #) ([(control x)] . #) 1 entry 0x8a2>)) The following example shows the results of calling `accessible-keymaps' on a large, complex keymap. Notice how some keymaps were given explicit names using `set-keymap-name'; those submaps without explicit names are given descriptive names indicating their relationship to their enclosing keymap. (accessible-keymaps (current-global-map)) => (([] . #) ([(control c)] . #) ([(control h)] . #) ([(control x)] . #) ([(meta escape)] . #) 3 entries 0x3e0>) ([(meta control \[)] . #) 3 entries 0x3e0>) ([f1] . #) ([(control x) \4] . #) ([(control x) \5] . #) ([(control x) \6] . #) ([(control x) a] . #) 8 entries 0x3ef>) ([(control x) n] . #) ([(control x) r] . #) ([(control x) v] . #) ([(control x) a i] . #) 8 entries 0x3ef>) 2 entries 0x3f5>)) - Function: map-keymap FUNCTION KEYMAP &optional SORT-FIRST This function applies FUNCTION to each element of `KEYMAP'. FUNCTION will be called with two arguments: a key-description list, and the binding. The order in which the elements of the keymap are passed to the function is unspecified. If the function inserts new elements into the keymap, it may or may not be called with them later. No element of the keymap will ever be passed to the function more than once. The function will not be called on elements of this keymap's parents (*note Inheritance and Keymaps::.) or upon keymaps which are contained within this keymap (multi-character definitions). It will be called on characters since they are not really two-character sequences. If the optional third argument SORT-FIRST is non-`nil', then the elements of the keymap will be passed to the mapper function in a canonical order. Otherwise, they will be passed in hash (that is, random) order, which is faster. - Function: keymap-fullness KEYMAP This function returns the number of bindings in the keymap. - Function: where-is-internal DEFINITION &optional KEYMAPS FIRSTONLY NOINDIRECT EVENT-OR-KEYS This function returns a list of key sequences (of any length) that are bound to DEFINITION in a set of keymaps. The argument DEFINITION can be any object; it is compared with all keymap entries using `eq'. KEYMAPS can be either a keymap (meaning search in that keymap and the current global keymap) or a list of keymaps (meaning search in exactly those keymaps and no others). If KEYMAPS is nil, search in the currently applicable maps for EVENT-OR-KEYS. If KEYMAP is a keymap, then the maps searched are KEYMAP and the global keymap. If KEYMAP is a list of keymaps, then the maps searched are exactly those keymaps, and no others. If KEYMAP is `nil', then the maps used are the current active keymaps for EVENT-OR-KEYS (this is equivalent to specifying `(current-keymaps EVENT-OR-KEYS)' as the argument to KEYMAPS). If FIRSTONLY is non-`nil', then the value is a single vector representing the first key sequence found, rather than a list of all possible key sequences. If NOINDIRECT is non-`nil', `where-is-internal' doesn't follow indirect keymap bindings. This makes it possible to search for an indirect definition itself. This function is used by `where-is' (*note Help: (emacs)Help.). (where-is-internal 'describe-function) => ([(control h) d] [(control h) f] [f1 d] [f1 f]) - Function: describe-bindings-internal MAP &optional ALL SHADOW PREFIX MOUSE-ONLY-P This function inserts (into the current buffer) a list of all defined keys and their definitions in MAP. Optional second argument ALL says whether to include even "uninteresting" definitions, i.e. symbols with a non-`nil' `suppress-keymap' property. Third argument SHADOW is a list of keymaps whose bindings shadow those of map; if a binding is present in any shadowing map, it is not printed. Fourth argument PREFIX, if non-`nil', should be a key sequence; only bindings which start with that key sequence will be printed. Fifth argument MOUSE-ONLY-P says to only print bindings for mouse clicks. `describe-bindings-internal' is used to implement the help command `describe-bindings'. - Command: describe-bindings PREFIX MOUSE-ONLY-P This function creates a listing of all defined keys and their definitions. It writes the listing in a buffer named `*Help*' and displays it in a window. If PREFIX is non-`nil', it should be a prefix key; then the listing includes only keys that start with PREFIX. When several characters with consecutive ASCII codes have the same definition, they are shown together, as `FIRSTCHAR..LASTCHAR'. In this instance, you need to know the ASCII codes to understand which characters this means. For example, in the default global map, the characters ` .. ~' are described by a single line. is ASCII 32, `~' is ASCII 126, and the characters between them include all the normal printing characters, (e.g., letters, digits, punctuation, etc.); all these characters are bound to `self-insert-command'. If the second argument (prefix arg, interactively) is non-`nil' then only the mouse bindings are displayed.  File: lispref.info, Node: Other Keymap Functions, Prev: Scanning Keymaps, Up: Keymaps Other Keymap Functions ====================== - Function: set-keymap-prompt KEYMAP NEW-PROMPT This function sets the "prompt" of KEYMAP to string NEW-PROMPT, or `nil' if no prompt is desired. The prompt is shown in the echo-area when reading a key-sequence to be looked-up in this keymap. - Function: keymap-prompt KEYMAP &optional USE-INHERITED This function returns the "prompt" of the given keymap. If USE-INHERITED is non-`nil', any parent keymaps will also be searched for a prompt.  File: lispref.info, Node: Menus, Next: Dialog Boxes, Prev: Keymaps, Up: Top Menus ***** * Menu: * Menu Format:: Format of a menu description. * Menubar Format:: How to specify a menubar. * Menubar:: Functions for controlling the menubar. * Modifying Menus:: Modifying a menu description. * Pop-Up Menus:: Functions for specifying pop-up menus. * Menu Filters:: Filter functions for the default menubar. * Menu Accelerators:: Using and controlling menu accelerator keys * Buffers Menu:: The menu that displays the list of buffers.  File: lispref.info, Node: Menu Format, Next: Menubar Format, Up: Menus Format of Menus =============== A menu is described using a "menu description", which is a list of menu items, keyword-value pairs, strings, and submenus. The menu description specifies which items are present in the menu, what function each item invokes, and whether the item is selectable or not. Pop-up menus are directly described with a menu description, while menubars are described slightly differently (see below). The first element of a menu must be a string, which is the name of the menu. This is the string that will be displayed in the parent menu or menubar, if any. This string is not displayed in the menu itself, except in the case of the top level pop-up menu, where there is no parent. In this case, the string will be displayed at the top of the menu if `popup-menu-titles' is non-`nil'. Immediately following the first element there may optionally be up to four keyword-value pairs, as follows: `:included FORM' This can be used to control the visibility of a menu. The form is evaluated and the menu will be omitted if the result is `nil'. `:config SYMBOL' This is an efficient shorthand for `:included (memq SYMBOL menubar-configuration)'. See the variable `menubar-configuration'. `:filter FUNCTION' A menu filter is used to sensitize or incrementally create a submenu only when it is selected by the user and not every time the menubar is activated. The filter function is passed the list of menu items in the submenu and must return a list of menu items to be used for the menu. It is called only when the menu is about to be displayed, so other menus may already be displayed. Vile and terrible things will happen if a menu filter function changes the current buffer, window, or frame. It also should not raise, lower, or iconify any frames. Basically, the filter function should have no side-effects. `:accelerator KEY' A menu accelerator is a keystroke which can be pressed while the menu is visible which will immediately activate the item. KEY must be a char or the symbol name of a key. *Note Menu Accelerators::. The rest of the menu consists of elements as follows: * A "menu item", which is a vector in the following form: `[ NAME CALLBACK :KEYWORD VALUE :KEYWORD VALUE ... ]' NAME is a string, the name of the menu item; it is the string to display on the menu. It is filtered through the resource database, so it is possible for resources to override what string is actually displayed. CALLBACK is a form that will be invoked when the menu item is selected. If the callback of a menu item is a symbol, then it must name a command. It will be invoked with `call-interactively'. If it is a list, then it is evaluated with `eval'. The valid keywords and their meanings are described below. Note that for compatibility purposes, the form `[ NAME CALLBACK ACTIVE-P ]' is also accepted and is equivalent to `[ NAME CALLBACK :active ACTIVE-P ]' and the form `[ NAME CALLBACK ACTIVE-P SUFFIX]' is accepted and is equivalent to `[ NAME CALLBACK :active ACTIVE-P :suffix SUFFIX]' However, these older forms are deprecated and should generally not be used. * If an element of a menu is a string, then that string will be presented in the menu as unselectable text. * If an element of a menu is a string consisting solely of hyphens, then that item will be presented as a solid horizontal line. * If an element of a menu is a string beginning with `--:', then a particular sort of horizontal line will be displayed, as follows: `"--:singleLine"' A solid horizontal line. This is equivalent to a string consisting solely of hyphens. `"--:doubleLine"' A solid double horizontal line. `"--:singleDashedLine"' A dashed horizontal line. `"--:doubleDashedLine"' A dashed double horizontal line. `"--:noLine"' No line (but a small space is left). `"--:shadowEtchedIn"' A solid horizontal line with a 3-d recessed appearance. `"--:shadowEtchedOut"' A solid horizontal line with a 3-d pushed-out appearance. `"--:shadowDoubleEtchedIn"' A solid double horizontal line with a 3-d recessed appearance. `"--:shadowDoubleEtchedOut"' A solid double horizontal line with a 3-d pushed-out appearance. `"--:shadowEtchedInDash"' A dashed horizontal line with a 3-d recessed appearance. `"--:shadowEtchedOutDash"' A dashed horizontal line with a 3-d pushed-out appearance. `"--:shadowDoubleEtchedInDash"' A dashed double horizontal line with a 3-d recessed appearance. `"--:shadowDoubleEtchedOutDash"' A dashed double horizontal line with a 3-d pushed-out appearance. * If an element of a menu is a list, it is treated as a submenu. The name of that submenu (the first element in the list) will be used as the name of the item representing this menu on the parent. The possible keywords are as follows: :active FORM FORM will be evaluated when the menu that this item is a part of is about to be displayed, and the item will be selectable only if the result is non-`nil'. If the item is unselectable, it will usually be displayed grayed-out to indicate this. :suffix FORM FORM will be evaluated when the menu that this item is a part of is about to be displayed, and the resulting string is appended to the displayed name. This provides a convenient way of adding the name of a command's "argument" to the menu, like `Kill Buffer NAME'. :keys STRING Normally, the keyboard equivalents of commands in menus are displayed when the "callback" is a symbol. This can be used to specify keys for more complex menu items. It is passed through `substitute-command-keys' first. :style STYLE Specifies what kind of object this menu item is. STYLE be one of the symbols `nil' A normal menu item. `toggle' A toggle button. `radio' A radio button. `button' A menubar button. The only difference between toggle and radio buttons is how they are displayed. But for consistency, a toggle button should be used when there is one option whose value can be turned on or off, and radio buttons should be used when there is a set of mutually exclusive options. When using a group of radio buttons, you should arrange for no more than one to be marked as selected at a time. :selected FORM Meaningful only when STYLE is `toggle', `radio' or `button'. This specifies whether the button will be in the selected or unselected state. FORM is evaluated, as for `:active'. :included FORM This can be used to control the visibility of a menu item. The form is evaluated and the menu item is only displayed if the result is non-`nil'. Note that this is different from `:active': If `:active' evaluates to `nil', the item will be displayed grayed out, while if `:included' evaluates to `nil', the item will be omitted entirely. :config SYMBOL This is an efficient shorthand for `:included (memq SYMBOL menubar-configuration)'. See the variable `menubar-configuration'. :accelerator KEY A menu accelerator is a keystroke which can be pressed while the menu is visible which will immediately activate the item. KEY must be a char or the symbol name of a key. *Note Menu Accelerators::. - Variable: menubar-configuration This variable holds a list of symbols, against which the value of the `:config' tag for each menubar item will be compared. If a menubar item has a `:config' tag, then it is omitted from the menubar if that tag is not a member of the `menubar-configuration' list. For example: ("File" :filter file-menu-filter ; file-menu-filter is a function that takes ; one argument (a list of menu items) and ; returns a list of menu items [ "Save As..." write-file] [ "Revert Buffer" revert-buffer :active (buffer-modified-p) ] [ "Read Only" toggle-read-only :style toggle :selected buffer-read-only ] )  File: lispref.info, Node: Menubar Format, Next: Menubar, Prev: Menu Format, Up: Menus Format of the Menubar ===================== A menubar is a list of menus, menu items, and strings. The format is similar to that of a menu, except: * The first item need not be a string, and is not treated specially. * A string consisting solely of hyphens is not treated specially. * If an element of a menubar is `nil', then it is used to represent the division between the set of menubar items which are flush-left and those which are flush-right. (Note: this isn't completely implemented yet.)  File: lispref.info, Node: Menubar, Next: Modifying Menus, Prev: Menubar Format, Up: Menus Menubar ======= - Variable: current-menubar This variable holds the description of the current menubar. This may be buffer-local. When the menubar is changed, the function `set-menubar-dirty-flag' has to be called in order for the menubar to be updated on the screen. - Constant: default-menubar This variable holds the menubar description of the menubar that is visible at startup. This is the value that `current-menubar' has at startup. - Function: set-menubar-dirty-flag This function tells XEmacs that the menubar widget has to be updated. Changes to the menubar will generally not be visible until this function is called. The following convenience functions are provided for setting the menubar. They are equivalent to doing the appropriate action to change `current-menubar', and then calling `set-menubar-dirty-flag'. Note that these functions copy their argument using `copy-sequence'. - Function: set-menubar MENUBAR This function sets the default menubar to be MENUBAR (*note Menu Format::.). This is the menubar that will be visible in buffers that have not defined their own, buffer-local menubar. - Function: set-buffer-menubar MENUBAR This function sets the buffer-local menubar to be MENUBAR. This does not change the menubar in any buffers other than the current one. Miscellaneous: - Variable: menubar-show-keybindings If true, the menubar will display keyboard equivalents. If false, only the command names will be displayed. - Variable: activate-menubar-hook Function or functions called before a menubar menu is pulled down. These functions are called with no arguments, and should interrogate and modify the value of `current-menubar' as desired. The functions on this hook are invoked after the mouse goes down, but before the menu is mapped, and may be used to activate, deactivate, add, or delete items from the menus. However, using a filter (with the `:filter' keyword in a menu description) is generally a more efficient way of accomplishing the same thing, because the filter is invoked only when the actual menu goes down. With a complex menu, there can be a quite noticeable and sometimes aggravating delay if all menu modification is implemented using the `activate-menubar-hook'. See above. These functions may return the symbol `t' to assert that they have made no changes to the menubar. If any other value is returned, the menubar is recomputed. If `t' is returned but the menubar has been changed, then the changes may not show up right away. Returning `nil' when the menubar has not changed is not so bad; more computation will be done, but redisplay of the menubar will still be performed optimally. - Variable: menu-no-selection-hook Function or functions to call when a menu or dialog box is dismissed without a selection having been made.  File: lispref.info, Node: Modifying Menus, Next: Pop-Up Menus, Prev: Menubar, Up: Menus Modifying Menus =============== The following functions are provided to modify the menubar of one of its submenus. Note that these functions modify the menu in-place, rather than copying it and making a new menu. Some of these functions take a "menu path", which is a list of strings identifying the menu to be modified. For example, `("File")' names the top-level "File" menu. `("File" "Foo")' names a hypothetical submenu of "File". Others take a "menu item path", which is similar to a menu path but also specifies a particular item to be modified. For example, `("File" "Save")' means the menu item called "Save" under the top-level "File" menu. `("Menu" "Foo" "Item")' means the menu item called "Item" under the "Foo" submenu of "Menu". - Function: add-submenu MENU-PATH SUBMENU &optional BEFORE This function adds a menu to the menubar or one of its submenus. If the named menu exists already, it is changed. MENU-PATH identifies the menu under which the new menu should be inserted. If MENU-PATH is `nil', then the menu will be added to the menubar itself. SUBMENU is the new menu to add (*note Menu Format::.). BEFORE, if provided, is the name of a menu before which this menu should be added, if this menu is not on its parent already. If the menu is already present, it will not be moved. - Function: add-menu-button MENU-PATH MENU-LEAF &optional BEFORE This function adds a menu item to some menu, creating the menu first if necessary. If the named item exists already, it is changed. MENU-PATH identifies the menu under which the new menu item should be inserted. MENU-LEAF is a menubar leaf node (*note Menu Format::.). BEFORE, if provided, is the name of a menu before which this item should be added, if this item is not on the menu already. If the item is already present, it will not be moved. - Function: delete-menu-item MENU-ITEM-PATH This function removes the menu item specified by MENU-ITEM-PATH from the menu hierarchy. - Function: enable-menu-item MENU-ITEM-PATH This function makes the menu item specified by MENU-ITEM-PATH be selectable. - Function: disable-menu-item MENU-ITEM-PATH This function makes the menu item specified by MENU-ITEM-PATH be unselectable. - Function: relabel-menu-item MENU-ITEM-PATH NEW-NAME This function changes the string of the menu item specified by MENU-ITEM-PATH. NEW-NAME is the string that the menu item will be printed as from now on. The following function can be used to search for a particular item in a menubar specification, given a path to the item. - Function: find-menu-item MENUBAR MENU-ITEM-PATH &optional PARENT This function searches MENUBAR for the item given by MENU-ITEM-PATH starting from PARENT (`nil' means start at the top of MENUBAR). This function returns `(ITEM . PARENT)', where PARENT is the immediate parent of the item found (a menu description), and ITEM is either a vector, list, or string, depending on the nature of the menu item. This function signals an error if the item is not found. The following deprecated functions are also documented, so that existing code can be understood. You should not use these functions in new code. - Function: add-menu MENU-PATH MENU-NAME MENU-ITEMS &optional BEFORE This function adds a menu to the menubar or one of its submenus. If the named menu exists already, it is changed. This is obsolete; use `add-submenu' instead. MENU-PATH identifies the menu under which the new menu should be inserted. If MENU-PATH is `nil', then the menu will be added to the menubar itself. MENU-NAME is the string naming the menu to be added; MENU-ITEMS is a list of menu items, strings, and submenus. These two arguments are the same as the first and following elements of a menu description (*note Menu Format::.). BEFORE, if provided, is the name of a menu before which this menu should be added, if this menu is not on its parent already. If the menu is already present, it will not be moved. - Function: add-menu-item MENU-PATH ITEM-NAME FUNCTION ENABLED-P &optional BEFORE This function adds a menu item to some menu, creating the menu first if necessary. If the named item exists already, it is changed. This is obsolete; use `add-menu-button' instead. MENU-PATH identifies the menu under which the new menu item should be inserted. ITEM-NAME, FUNCTION, and ENABLED-P are the first, second, and third elements of a menu item vector (*note Menu Format::.). BEFORE, if provided, is the name of a menu item before which this item should be added, if this item is not on the menu already. If the item is already present, it will not be moved.  File: lispref.info, Node: Menu Filters, Next: Menu Accelerators, Prev: Pop-Up Menus, Up: Menus Menu Filters ============ The following filter functions are provided for use in `default-menubar'. You may want to use them in your own menubar description. - Function: file-menu-filter MENU-ITEMS This function changes the arguments and sensitivity of these File menu items: `Delete Buffer' Has the name of the current buffer appended to it. `Print Buffer' Has the name of the current buffer appended to it. `Pretty-Print Buffer' Has the name of the current buffer appended to it. `Save Buffer' Has the name of the current buffer appended to it, and is sensitive only when the current buffer is modified. `Revert Buffer' Has the name of the current buffer appended to it, and is sensitive only when the current buffer has a file. `Delete Frame' Sensitive only when there is more than one visible frame. - Function: edit-menu-filter MENU-ITEMS This function changes the arguments and sensitivity of these Edit menu items: `Cut' Sensitive only when XEmacs owns the primary X Selection (if `zmacs-regions' is `t', this is equivalent to saying that there is a region selected). `Copy' Sensitive only when XEmacs owns the primary X Selection. `Clear' Sensitive only when XEmacs owns the primary X Selection. `Paste' Sensitive only when there is an owner for the X Clipboard Selection. `Undo' Sensitive only when there is undo information. While in the midst of an undo, this is changed to `Undo More'. - Function: buffers-menu-filter MENU-ITEMS This function sets up the Buffers menu. *Note Buffers Menu::, for more information.